Brake system with anti-lock control and traction slip control

Abstract

A brake system with anti-lock control and traction slip control is disclosed. The system includes a braking pressure generator composed of a master cylinder and a brake power booster. Also provided is an auxiliary-pressure supply system which generates an auxiliary pressure proportional to the pedal force for anti-lock control and generates an uncontrolled predetermined auxiliary pressure for traction slip control. The wheel brakes of the front wheels are connected to the master cylinder. By way of valve assemblies, the auxiliary-pressure supply system is connected to the wheel brakes of the front wheels in the control phases. The rear-wheel brake circuit is designed as a dynamic circuit and is fed directly by the auxiliary-pressure supply system.

What is claimed is: 
     
       1. A brake system with anti-lock control and traction slip control for automotive vehicles including front and rear wheel brakes, said system comprising, in combination: a pedal-actuated master cylinder having first and second working chambers respectively connected to the front wheel brakes by way of first and second normally open control valves (11, 13);   an unpressurized reservoir;   an auxiliary pressure source having a normally open shut-off valve (8) and a pressure control valve (7) serially coupled between a suction side and a pressure side of said pressure source;   first and second non-return valves respectively connected between said pressure side of said pressure source and said front wheels;   a third non-return valve connected between said pressure side of said pressure source and the rear wheel brakes;   said pressure control valve (7) having a pressure control input connected to one of said working chambers and being operative to close the serial connection of said pressure control valve (7) and said shut-off valve (8) proportionally in response to pressure in said one of said working chambers;   a plurality of normally open pressure control valves respectively connected between said non-return valves and said wheel brakes;   a plurality of normally closed pressure control valves respectively connected between said reservoir and said wheel brakes; and,   said plurality of normally open valves and said plurality of normally closed valves being responsive to anti-lock control and traction slip control signals to provide brake pressure variation in response thereto.   
     
     
       2. The brake system according to claim 1 wherein said first and second working chambers are respectively connected to the front wheel brakes by way of a first and second pair of serially connected normally open control valves. 
     
     
       3. The brake system according to claim 2 wherein the common connections of said first and second pairs of serially connected control valves are respectively further connected to said auxiliary pressure source by way of said first and second non-return valves.